From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id C30F5C433EF for ; Tue, 12 Jun 2018 14:49:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E998208B1 for ; Tue, 12 Jun 2018 14:49:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7E998208B1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754367AbeFLOtT (ORCPT ); Tue, 12 Jun 2018 10:49:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:44811 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754257AbeFLOtS (ORCPT ); Tue, 12 Jun 2018 10:49:18 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext-too.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id EE9A2AC8A; Tue, 12 Jun 2018 14:49:16 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id BCEF01E0D63; Tue, 12 Jun 2018 16:49:16 +0200 (CEST) Date: Tue, 12 Jun 2018 16:49:16 +0200 From: Jan Kara To: Zhouyang Jia Cc: Jan Kara , Amir Goldstein , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fsnotify: add error handling for kmem_cache_create Message-ID: <20180612144916.5vuqy3v6nrtcxksh@quack2.suse.cz> References: <1528776964-39826-1-git-send-email-jiazhouyang09@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1528776964-39826-1-git-send-email-jiazhouyang09@gmail.com> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 12-06-18 12:16:04, Zhouyang Jia wrote: > When kmem_cache_create fails, the lack of error-handling code may > cause unexpected results. > > This patch adds error-handling code after calling kmem_cache_create. > > Signed-off-by: Zhouyang Jia > --- > fs/notify/dnotify/dnotify.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c > index 63a1ca4..216b411 100644 > --- a/fs/notify/dnotify/dnotify.c > +++ b/fs/notify/dnotify/dnotify.c > @@ -387,6 +387,9 @@ static int __init dnotify_init(void) > dnotify_struct_cache = KMEM_CACHE(dnotify_struct, SLAB_PANIC); > dnotify_mark_cache = KMEM_CACHE(dnotify_mark, SLAB_PANIC); > > + if (!dnotify_struct_cache || !dnotify_mark_cache) > + return -ENOMEM; > + Caches are allocated with SLAB_PANIC - i.e., we panic the system if caches cannot be created. And that's intended since something is really wrong with the system in that case. So this check is pointless. Honza > dnotify_group = fsnotify_alloc_group(&dnotify_fsnotify_ops); > if (IS_ERR(dnotify_group)) > panic("unable to allocate fsnotify group for dnotify\n"); > -- > 2.7.4 > -- Jan Kara SUSE Labs, CR